In general, an air conditioning system is provided in an interior of an automobile and used to adjust the temperature of the vehicle interior depending on a season.
Cold and hot air generated by the air conditioning system is discharged into the vehicle interior by being introduced into an air ventilation opening provided in a console and an instrument panel installed in the interior of the automobile through a duct.
Meanwhile, by installing, in the air ventilation opening, an air vent including a damper for adjusting an opening level of the duct, a knob for adjusting a movement of the damper, and a housing coupled to be fixed to the front of the duct in which the knob is provided, a person in the vehicle interior may control the knob to adjust the opening level of the duct and the air direction and thereby adjust an amount of air to be discharged.
However, such an existing air vent has a low visibility and thus, it is difficult to determine whether the air vent is open or closed, during night driving with an insufficient quantity of light in an interior.
Thus, in the past, to solve the issue described above, a light emitting device for an air vent of an automobile including an LED for emitting light while being supplied with power from a battery, a light guide for guiding the light generated by the LED, a diffusion plate for widely diffusing the light guided by the light guide, and an air vent housing having an irradiation hole formed therethrough to allow the light that is widely diffused by the diffusion plate to be irradiated to the outside of the air vent was developed and used.
In the existing light emitting device for an air vent of an automobile, the diffusion plate is inserted into the irradiation hole to be fixed in a direction from the rear to the front of the air vent housing, the light guide is installed in the rear of the diffusion plate inserted into the irradiation hole, and the LED for emitting light while being supplied with power from the battery is installed on one side of the light guide installed in the diffusion plate. When the LED emits light, the light generated by the LED is guided to the other side of the light guide and widely diffused by the diffusion plate at the same time, and thereby irradiated to the outside of the air vent housing of the air vent through the irradiation hole.
However, in the existing light emitting device for an air vent of an automobile, since the irradiation hole, the diffusion plate, and the light guide formed in the air vent housing are formed in the same length, when the light emitted from the LED is directly supplied to one side of a light emitting portion, the light irradiated to the one side of the light emitting portion is irradiated bright through the one side of the irradiation hole formed in the air vent housing at first, and the remaining light is irradiated while moving to the other side of the light guide, the other side of the diffusion plate, and the other side of the irradiation hole. Thus, an illuminance of a site to which the light of the LED is irradiated directly is bright, whereas an illuminance of the light irradiated through the one side and the other side of the irradiation hole is dark, and thus the overall illuminance of the diffusion plate is not uniform.
Meanwhile, in the past, the non-uniform illuminance of the light irradiated through the one side and the other side of the irradiation hole degraded the appearance of the vehicle interior and lowered the marketability of the vehicle.